Insulator covered with a protective envelope



INSULATOR COVERED WITH A PROTECTIVE ENVELOPE 2 Sheets-Sheet l 31' 1 edNov. 25, 1964 April 1967 w.' c. GREGORY 3,315,026

INSULATOR COVERED WITH A PROTECTIVE ENVELOPE Filed Nov. 25, 1964- 2Sheets-Sheet 2 Jam; 0%,,

space with an elastomer contract.

United States Patent INSULATOR COVERED WITH A PROTECTIVE ENVELOPE Thisapplication is a continuation-in-part of my prior copending applicationSer. No. 70,685 filed Nov. 21, 1960, and now abandoned.

A path to Ground is made when out-door insulators that are covered withsoluble dust are wetted by natural precipitation. Short circuits may bevery expensive.

The object of this invention is to provide means for maintaining theresistance of insulators the same as when new or BETTER.

Another Object sulator that shall cheap to make.

Another object of this invetnion is to break the film of water that runstowards an insulator during a storm.

Another object of this invention is to provide protection for insulatorsby enclosing the insulator in a self-cleaning envelope.

Still another object of this invention is to change electrolytes formedon dirt covered insulators in wet weather to non-electrolytes.

These and other objects of this invention will be apparent from thefollowing specification when taken with the accompanying drawings, inwhich: I

FIGURE 1 shows a cap stud insulator. The cap is separated from the studby filling the space with a nonconducting material.

FIGURE 2 shows of this invention is to provide an inbe light in Weight,simple, durable and sectional views, at different parts, 2A, 2B, 2C and2D of the insulator for FIGURE 1.

FIGURE 3 shows a cap-stud insulator. The cap and stud are separatedmechanically and electrically by filling the space with a rigidnon-conducting resin.

FIGURE 4 shows a one-time casting. In this embodiment the conductingmembers are separated mechanically and electrically by filling the spacewith a suitable rigid non-conducting resin.

FIGURE 5 shows a self-cleaning two-link-stud insulator. The links inthis insulator are separated by filling the or a plastic elastomer.

FIGURE 6 shows an'auto-cleaning poly-link-stud insulator. The links inthis insulator are separated mechanically and electrically with anelastomer. FIGURE 7 shows 'a self-cleaning accordion type envelope. Theever changing air pressure within the envelope causes the surface of theenvelope to expand and This movement of the outer surface does notpermit the accumulation of dust.

FIGURE 8A shows an auto-cleaning envelope that consists of a pluralityof sealed tubes cast into the form of an envelope.

FIGURE 8B shows a self-cleaning envelope, the walls of said envelopehaving various thicknesses.

FIGURES 9A and 9B are sectional views through 8A and 8B.

FIGURE 10 shows an auto-cleaning envelope that consists of a largenumber of balloons incorporated with an elastormer to form an envelope.

FIGURE 11 shows an auto-cleaning envelope that consists of a cylindricalelastomer tube sealed at both ends and to a supporting wire.

FIGURE 12 shows the end view looking toward the left of FIGURE ll.

3,315,026 Patented Apr. 18, 1967 FIGURES 1, 2, 3, and 4 illustrate acap-stud tension type rigid insulator. The metal members of theinsulator are separated mechanically and electrically with anonconducting, non-metallic rigid member. The outer surfaces of theseinsulators are designed so that a continuous film of an electrolyte(water and a soluble dust) can not form between the metal studs, therebymaintaining the original resistance.

FIGURES 5 and 6 show a self-cleaning link-stud tension type insulator.In these embodiments the links are kept separated mechanically andelectrically by a non-conducting elastomer or a combination of plasticsand elestomers. The outer surface of these insulators are so designedthat a continuous film of an electrolyte (soluble dust dissolved in rainwater) metal studs, thereby maintaining the original resistance.

FIGURES 7 through 12 show the mechanical Ways of preventing theaccumulation of dust on insulating members. Electrolytes are formed oninsulators when soluble dusts are dissolved by various form of naturalprecipitation. When dust is absent electrolysis can not form. With wateronly, no shorting occurs.

FIGURES 7 thru 12 show mechanical methods of eliminating theaccumulation of dust on insulating memers.

FIGURES 1, 2, 3 dead-end service.

FIGURES 6, 8A, 8B, 9A and 9B are designed for vertical or linesupporting service.

FIGURES 7, 10, 11 and 12 could horizontal and/ or vertical service.

FIGURES 1, 2, 3 and 4 could be classified as rigid insulators. Theinsulator consists of the metal members (or conductors) and thenon-metallic members (insulating materials). The metal members may be ofthe ferrous family or the non-ferrous family of metals, such as copper,aluminum, magnesium and the like. The insulating materials may vary fromcommercially pure non-conducting organic materials to commercially purenon-conducting inorganic materials. The organic materials may be of athermoplastic or thermo-setting plastic series and may vary fromcommercially pure plastic to a plastic heavily loaded withnon-conducting fillers. A short list of the rigid plastics that could beused would be the co-polymers of a-crylonitrile or styrene series,cellulose acetate, diallyl phthalates, halogenated hydrocarbons,melamine-formaldehyde, the methacrylates, phenol-formaldehyde, the epoxyfamily and a host of others. The inorganic non-conducting materialscould be the inorganic non-conducting cements that when set arenon-conductors and non-absorbers of Water. The properties most and 5 aredesigned for horizontal or be used in either sulators. a non-metalnon-conducting member. The metal member may be of the ferrous family orthe non-ferrous family of metals such as copper, aluminum, magnesium andthe like. The non-conducting member of the insulator family is either anelastomer or a mixture of an elastomer and a plastic. The elastomers maybe loaded with non-conducting fillers. A partial list of thevulcanizable elastomers that could be used includes natural rubber,thiokols, neoprene, styrene family or rubbers, silicone rubbers,acrylate rubbers, Hypalon, chlorinated and/or fluorinated rubbers andthe like.

FIGURES 7 through 12 illustrate a flexible envelope that covers aninsulator. These envelopes may be of the vulcanizable elastomers familyor the flexible plastics which are mostly of the thermoplastic type butdo not vulcanize, such as polyvinyl chloride, polyvinyl butyral,polyethylene and the chlorinated and fluorinated hydrocarbons, e.g., theTeflon family.

FIGURE 1 illustrates a tension type cap-stud insulator. The stud 1 iswelded 2 to the anchor plate 3 after the anchor plate has been placedwithin the shell 4 of the cap. The end 5 of the cap is then welded 6 tothe said shell. Water-film breakers 7 are shown on the exposed hardware.The hardware or metal conducting parts are separated mechanically andelectrically by covering the anchor plate 3 within the cap assembly 4and 5 with a mechanically strong resin and one that has great insulatingproperties, such as a suitable epoxy resin, a thermoplastic and/ orthermosetting resin.

The plastic portion of this insulator may be extended thereby enclosinga portion of the insulator with the resin as at 8. When naturalprecipitation accumulates on dust covered insulators, at least part ofthe dust dissolves to form an electrolyte. This electrolyte, if notbroken, will form a path for the current to run over or are across theinsulator. This path can be broken with properly designed water-filmbreakers 9.

FIGURE 2 shows the cross-section of the FIGURE 1, at sections 2A, 2B, 2Cand 2D.

FIGURE 3 is an embodiment of a cap-stud insulator. In this embodimentthe stud 10 is screwed into the anchor plate 11, after it has beeninserted within the shell 12. The metal portion of the insulator iscompleted after welding 13 to the end of the cap 14 and the shell 12.The metal parts of the insulator are held apart mechanically andelectrically by enclosing the parts with a tailored resin for aparticular job 01' area. Efficient water-film breakers 15, 16 and 17 areshown in FIGURE 4. The hardware in this embodiment is a one-timecasting. After the molding sand is removed from the casting, and thecasting cleaned, the hardware 18 and 19 can be embedded with a suitableresin 20. The resin may be cast to form a plurality of water-filmbreakers 21. It is also desirable to have water-film breakers on thehardware 22.

FIGURE 5 shows a two-chain-link-stud insulator. In this embodiment studs23 are welded onto the links 24. The links are held apart mechanicallyand electrically by enclosing with a suitable resin and/ or elastomer25. The finished insulator should have a plurality of water-filmbreakers.

FIGURE 6 shows an insulator of the chain-link type having a plurality oflinks. In this embodiment the links 27 are held apart mechanically andelectrically with an elastomer 28. The finished outer surface of theinsulator should have a plurality of water-film breakers 29.

FIGURES 5 and 6 are self-cleaning insulators. As the supporting wiressway in the wind, the elastomers stretch and contract in such a mannerthat particles of dirt are dislodged and made to fall off. Since therain has no material to dissolve to form an electrolyte, the rain runsoff as water without doing any damage.

FIGURE 7 shows how insulators may be kept clean and not lose theirresistance by enclosing them in an auto-cleaning envelope. In thisembodiment the envelope 30 is made to enclose the insulator 31 and thensealed at both ends 32. The wall of the envelope has corrugations 33 andis preferably black so as to adsorb the maximum amount of heat energy.The energy from the sun heats the air within the envelope and expandsthe surface of the envelope. At night the air is cooler, therebycontracting the envelope. This swelling and contracting breaks loose anydust particles. The envelope should be made of a plastic, that is wettedwith water with difficulty, e.g., a fluorinated hydrocarbon, e.g.,Teflon.

FIGURE 8A is an envelope made up of a plurality of cylindrical sealedtubes 34 made into an envelope 35. This envelope is made to enclose theinsulator 36. The outer surface of this envelope is coated alternatelywith insulator of a heat absorbing material 37, e.g., black paint, and aheat repellant material 38 e.g., white paint. The difference in the heatenergy absorbed will make the cylinders distort the envelope unevenly,thus causing foreign materials such as dust particles to fall off. Theareas of black and white should be approximately the same size and thedesign should be evenly and equally spaced.

FIGURE 9A shows the cross-section through 9A-9A.

FIGURE 8B shows an envelope 39 made up of the same plastic elastomermaterial but having different areas thicker than the adjoining areas.The areas of thick walls and thin walls should be approximately the samesize and the design should be evenly and equally spaced. The thicknessshould be such as to flex readily with a slight change of internalpressure. The envelope 39 is shown enclosing the insulator 40. Awater-film breaker 41 is shown between the corrugations.

FIGURE 9B is a cross-section of FIGURE SE at 9B-9B.

FIGURE 10 is an envelope made by having a plurality of small balloons 42cemented together with an elastomer to form a structure 43 capable ofcontracting and expanding with the change of atmospheric temperature andpressure.

To increase these changes to a maximum, alternate areas on the surfaceof the envelope are coated with an energy absorbing surface 44 and anenergy repelling surface 45. The drawing shows an insulator 46 encasedin the envelope. A foam, the cavities of which are non-conducting, couldbe substituted for the balloon structure.

FIGURE 11 shows an insulator 47 encased in a flexible envelope 48. Inthis embodiment, the ends are sealed together and to the supportingwires. The fins that are formed by the sealing process act as vanes inthe wind. The envelope should be made of an elastomer or a plasticelastomer.

FIGURE 12 is an end view of FIGURE 11, looking toward your left.

The resistance of insulators and insulating envelopes can be increasedby covering the outer surface with a grease-like material. Thisgrease-like material may act in two ways, namely (A) mechanically, (B)and/or chemically. (A) The grease-like material used mechanically may bea hydrocarbon,--C--C--C--, and/ or a silicone, Si-SiSi-. The viscosityof the material should be about 10 S.A.E. when used in a spray gun tospray insulators supporting energizing wires. The advantage siliconegrease has over a hydrocarbon grease is the silicone grease does notdeposit a graphite streak on the insulator should a flash-over occur. Byspraying the surface of an insulator with a grease-like material, watercan not wet the surface but will run off in the spheroidal state. (B)Chemically. This increased resistance is obtained chemically by changingthe water soluble dust particles that are dissolved in rain water andthat forms an electrolyte into a non-electrolyte. The water-solubledusts that are found around industrial cities and near bodies of saltwater are innumerable. These water soluble dusts accumulate on theinsulators. At night or on the first precipitation the soluble dustsdissolve to form electrolytes and at that moment electric energy startstoward ground." However, if this electrolyte is changed immediately to anon-electrolyte this shorting does not occur. For example, insulatorsnear a salt water body, the salt spray, carried by the wind, settles onthe insulators and evaporates, leaving finely divided crystals of salt.A heavy dew falls and the crystals dissolve forming an electrolyte. Nowif the insulator is coated withsay a silver stearate the electrolyte ischanged to a non-electrolyte thus:

Silver stearate-l-sodium chloride =sodium stearate+silver chlorideSodium stearate (a soap) is soluble enough to run off the i sulat r andat the Same time wash the surface clean.

' pellant, flexible material Again, near a potash plant, the dust ofpotassium salts settles on insulators for miles around. In this case anorganic ester could be used, for example:

Methyl stearate-f-potassium hydroxide =potassium stearate-l-methylalcohol There are thousands of other combinations that could be used.Stearic products are relatively cheap, difiiculty soluble in water butsoluble in alcohols. It is advisable to use material that is difficultlysoluble in water but soluble in an organic solvent e.g., an alcohol. Thesalt, ester or other compound when dispersed for spraying should have aconsistency so that it can be sprayed from a conventional air spray gun,similar to conventional lubricating oils sold as S.A.E. 10.

I claim:

1. An insulator comprising a first central terminal element made ofelectrically conductive material, a second central terminal element madeof electrically conductive material, a substantially rigid dielectricmaterial binding a portion of said first and second terminal elementstogether in a fixed relative position wherein said terminal elements arespaced and insulated from each other by said dielectric material toprovide a spaced juncture, an envelope made of electricallynonconductive, water resealingly engaged at opposite ends to said firstand second central terminal elements respectively, and spaced from thejuncture of said terminals and the dielectric binder material which arecompletely encapsulated by said envelope, wherein said envelope isformed with adjacent alternatively varying expansion means which causeit to expand and to contract automatically in response to atmospherictemperature variations so as to substantially dislodge dust particlessettling thereon.

2. An insulator as defined in claim 1 wherein the outer surface of theenvelope thereof is covered by a thin film of an electricallynonconductive grease-like substance selected from the group consistingof substantially water insoluble hydrocarbons and silicones.

3. An insulator as defined in claim 1 wherein said envelope is formedwith a plurality of annular corrugations which provide the means whichcauses said envelope to expand and to contract.

4. An insulator as defined in claim 1 wherein the outer surface of saidenvelope is provided with a plurality of alternating heat absorbing andheat reflecting areas which provide the means which causes said envelopeto expand and to contract.

5. An insulator as defined in claim 1 wherein the envelope is formedwith alternating relatively thick and thin areas which provide the meanswhich causes said envelope to expand and to contract.

6. An insulator as defined in claim 1 wherein the envelope is formedwith a plurality of internal sealed tubes with electricallynonconductive interiors which provide the means which causes saidenvelope to expand and to con-tract.

7. An insulator as defined in claim 1 wherein the envelope is formedwith a plurality of internal, resiliently bounded, sealed cavitieshaving electrically nonconductive interiors which provide the meanswhich causes said envelope to expand and to contract.

References Cited by the Examiner UNITED STATES PATENTS 467,941 2/1892Lee 174-184 474,569 5/ 1892 Anderson 174185 476,193 5/1892 Elliott174185 834,392 10/1906 Mead 174185 1,166,391 12/1915 Stein-berger174-180 1,717,281 6/1929 Thomson 174-184 X 1,728,531 9/ 1929 Estorff.1,806,854 5/1931 Hesson 17430 X FOREIGN PATENTS 9,517 1904 GreatBritain. 213,005 3/ 1924 Great Britain. 385,699 1/ 1933 Great Britain.426,212 3/ 1935 Great Britain. 740,93 8 11/ 1955 Great Britain.

LARAMIE E. ASKIN, Primary Examiner.

1. AN INSULATOR COMPRISING A FIRST CENTRAL TERMINAL ELEMENT MADE OFELECTRICALLY CONDUCTIVE MATERIAL, A SECOND CENTRAL TERMINAL ELEMENT MADEOF ELECTRICALLY CONDUCTIVE MATERIAL, A SUBSTANTIALLY RIGID DIELECTRICMATERIAL BINDING A PORTION OF SAID FIRST AND SECOND TERMINAL ELEMENTSTOGETHER IN A FIXED RELATIVE POSITION WHEREIN SAID TERMINAL ELEMENTS ARESPACED AND INSULATED FROM EACH OTHER BY SAID DIELECTRIC MATERIAL TOPROVIDE A SPACED JUNCTURE, AN ENVELOPE MADE OF ELECTRICALLYNONCONDUCTIVE, WATER REPELLANT, FLEXIBLE MATERIAL SEALINGLY ENGAGED ATOPPOSITE ENDS TO SAID FIRST AND SECOND CENTRAL TERMINAL ELEMENTSRESPECTIVELY, AND SPACED FROM THE JUNCTURE OF SAID TERMINALS AND THEDIELECTRIC BINDER MATERIAL WHICH ARE COMPLETELY ENCAPSULATED BY SAIDENVELOPE, WHEREIN SAID ENVELOPE IS FORMED WITH ADJACENT ALTERNATIVELYVARYING EXPANSION MEANS WHICH CAUSE IT TO EXPAND AND TO CONTRACTAUTOMATICALLY IN RESPONSE TO ATMOSPHERIC TEMPERATURE VARIATIONS SO AS TOSUBSTANTIALLY DISLODGE DUST PARTICLES SETTLING THEREON.